When memory and justice fail us

Think back to the last time you went on a mission to stock up on supplies due to COVID-19. What route did you take around the store? Can you describe the employee who bagged your groceries? What was the make and model of the car parked next to you? 

It’s likely this memory is difficult to retrieve and the details surrounding it have faded. After all, this was a stressful and uncertain time and your focus might have been elsewhere. It was some time ago and you have probably forgotten. 

Now, consider that these are the exact situations that eyewitnesses often find themselves in when being expected to make accurate and confident judgments about what they saw during a courtroom examination or a police interview.

This grocery store example demonstrates that memory is unreliable. We forget — a lot. Many of us assume everything we see is recorded and stored, waiting to be retrieved when needed. Empirical evidence indicates otherwise, even if we are highly confident. 

The reasons we forget, the types of inaccuracies we make and the malleability of memory are well understood by cognitive psychologists. We have been studying memory processes for decades. Despite these well-established memory fallibilities, eyewitness memory remains an important piece of admissible evidence in many criminal trials — sometimes it is the only evidence. 

A witness recalls seeing the defendant in the vicinity of the crime or committing the crime, or the victims themselves identify the perpetrator through police procedures like suspect lineups. One of the most controversial practices is the use of hypnosis to retrieve “repressed” memories buried in our subconscious. In many states this practice is inadmissible, but in some states (including Texas, Wyoming and Connecticut) it is admissible — even in cases of capital punishment. This was recently reported in a Dallas Morning News investigation.

You may have originally stored details of your grocery store trip, but due to the passage of time and relative dormancy of these memories, many of these details have been largely forgotten. Sometimes, they are never stored in the first place. Research indicates that not all information we encounter is encoded into long-term memory, so our recall is highly dependent on our limited attentional systems. If our minds are wandering, focused on other aspects of a scene, or a detail seems inconsequential at the time, no amount of hypnosis, prodding, or questioning will bring back memories that simply never existed.

The biggest problem is not memory abilities themselves, but with procedures that law enforcement may use to probe memory. By the time a witness testifies, they have often been questioned repeatedly, asked to choose faces from various lineups (sometimes with feedback from police) and potentially discussed the event with friends, family and the media.

Every aspect of this process has the potential to alter the witness’s original memory while, at the same time, strengthening the witness’s certainty. In her memoir “Picking Cotton,” Jennifer Thompson, recounts these exact police proceedings that contributed to her extreme confidence in her memory while simultaneously picking the wrong man as her attacker, twice. Our memories are susceptible to interference and distortion in a number of ways. Our memory systems are limited — we can’t, and don’t, remember every detail, so by filling in missing pieces from semantic knowledge, beliefs, biases and suggestions, our brain’s reconstruct our memories. 

We can generate memories for entire events that never happened even when impervious to hypnosis, and there is no evidence that memories brought to light during a hypnosis session are accurate.

Complications arise when DNA or other types of evidence are not available to corroborate victim memory and eyewitness accounts. In these cases, eyewitness memory and hypnosis should carry only the questionable weight they deserve, especially when potentially innocent people are facing capital punishment. 

The Innocence Project is a nonprofit organization committed to using DNA evidence to exonerate individuals who have been wrongfully convicted. This organization alone has now overturned 367 wrongful convictions, of which over 250 (69 percent) involved faulty eyewitness identification. This highlights that it is time for the justice system to make better use of cognitive psychology research on attention, learning and memory.

Let’s use evidence from psychological science to reform police practices such as eyewitness questioning, lineup procedures and use of hypnosis, not just in some states, but across the United States. As citizens, you may be called to jury duty or find yourself as a witness or victim of a crime. Be mindful of the limitations of your attention and memory systems, as well as possibly misleading police procedures that can seriously impact testimonies. 

As we face a pandemic and the profound changes coming from civil unrest, this endeavor may seem insignificant or ill-timed. But make no mistake, these memory errors and mistaken identities impact people of color substantially. Of the 367 cases overturned by the innocence project, 42 percent involved a cross-racial misidentification. African Americans are overrepresented in the prison system, making up 38 percent of incarcerated inmates, but only approximately 13 percent of the United States general population.

Now that people are reconsidering police procedures and practices, this is the most opportune time to reevaluate and improve these imperfect procedures.

Holly Bowen is an assistant professor in the Department of Psychology at SMU Dallas where she teaches and directs research on topics including memory, emotion, motivation and aging.